21576961937 has 2 divisors, whose sum is σ = 21576961938. Its totient is φ = 21576961936.

The previous prime is 21576961919. The next prime is 21576961999. The reversal of 21576961937 is 73916967512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16135096576 + 5441865361 = 127024^2 + 73769^2 .

It is a cyclic number.

It is not a de Polignac number, because 21576961937 - 2¹⁰ = 21576960913 is a prime.

It is not a weakly prime, because it can be changed into another prime (21576951937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10788480968 + 10788480969.

It is an arithmetic number, because the mean of its divisors is an integer number (10788480969).

Almost surely, 2^21576961937 is an apocalyptic number.

It is an amenable number.

21576961937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21576961937 is an equidigital number, since it uses as much as digits as its factorization.

21576961937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4286520, while the sum is 56.

The spelling of 21576961937 in words is "twenty-one billion, five hundred seventy-six million, nine hundred sixty-one thousand, nine hundred thirty-seven".